This invention relates to a component changing apparatus serving a group of injection molding machines, each having a mold clamping space receiving a mold which has opposite clamping plates and which is adapted to be tightened in the mold clamping space. Further, each injection molding machine has a horizontally oriented injection molding unit which may be placed into a withdrawn, lowered support position and which has a plasticizing unit that can be coupled to and uncoupled from the other components of the injection molding unit. The component may be a mold or another unit of an injection molding machine, such as a plasticizing unit. Each injection molding machine further has a mold changing table adjoining the rear end of the associated injection molding machine. Each mold changing table has mold guides for guiding the molds to two mold placements defined on the mold changing table. The mold changing tables are shiftable parallel to the injection molding axis of the respective injection molding machines in such a manner that their mold guides form, alternatingly with a mold guide in the clamping space, a conveying path (transport track) which is oriented perpendicularly to the injection molding axis. The mold may be shifted on the transport track by means of a mold shifting device for displacement from the clamping space to the mold changing table and conversely. The mold changing apparatus further has a mold magazine having a number of storage compartments as well as a transport device for transporting the molds between the mold changing tables and the mold storage compartments.
In a mold changing apparatus of the above-outlined type, as disclosed, for example, in German Patent No. 3,242,269 to which correspond U.S. Pat. No. 4,462,783 and Canadian Patent No. 1,212,213, one of the two emplacements of the mold changing table serves alternately as a conditioning space for the preheating and other preparation of the mold to be inserted into the clamping space of the injection molding machine. During the mold changing operation the mold movements are programcontrolled and are thus fully automated in the zone of the mold clamping space and the mold changing table. For transferring the mold removed from its injection molding machine to the mold magazine (mold storage device), however, an integration of the control in the entire mold changing program is not readily feasible because the mold storage device need not be situated in a predetermined spatial relationship relative to the injection molding machine.
A similar mold changing apparatus is disclosed in published European application No. 92,686 wherein, as illustrated in FIG. 11, the mold is moved from the mold clamping space immediately to a rail-mounted carriage situated at the same level and moved thereon to the mold magazine.
In another known changing apparatus for replacing working units (molds or plasticizing units) at least at one injection molding unit, a frame stand straddles the injection molding machine as well as an adjacent magazine for such units. On the frame stand there is arranged a bridge crane which is movable transversely to the injection molding axis and which has a trolley movable parallel to the injection molding axis. The trolley has a vertically movable carrier arm with a gripper device. During transport of the units from the injection molding machine to the magazine, the units are suspended from a carrier arm of the trolley and thus necessarily travel over areas occupied by operating personnel. Such an apparatus is disclosed in European Patent No. 69,221.
As disclosed in German Offenlegungsschrift (non-examined published application) No. 1,629,746, it is further known to transport molds by means of a rotary table from an automatic injection molding machine into storage compartments of an adjacent magazine. The rotary table may be vertically moved in a carrier column to the level of the superimposed storage compartments.